[EN]The main objective of the project described in this document is to get as a final product a free software and open source calendar system, that fulfills its mission efficiently. It is thought to give all basic functionalities that other calendar applications have. Another goal of the current project is to design and deploy some new functionalities, for example: event filtering when an authorized user tries to insert them into another user calendar, public calendar creation to use them as a base schema or as a model. Those calendars need to be capable of update themselves from year to year. To reach this objective, the idea is to reuse an existing open source project. A secondary goal is to fix the bugs that this base project might have.